The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important ... more The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important part of a PV generation chain. In order to track maximum power from the solar arrays, it is necessary to control the output impedance of the PV panel, so that the circuit can be operated at its Maximum Power Point (MPP), despite the unavoidable changes in the climate conditions such as temperature and Irradiance. A new MPPT analog technique to track the Maximum Power Point (MPP) of PV arrays is proposed. This new technique uses simple and classical functions of electronic circuits. An Off-Grid PV system was considered to apply and validate the proposed new technique. The entire circuit was implemented in circuit-oriented simulator Proteus-ISIS. We present the results associated with the design, the realization, and the experimentation of a PV system equipped with a new analog MPPT command. The obtained results have shown good efficiency of analog technique (more than 98.5%). The second p...
A device and method for threshold voltage programming of an Ion Sensitive Field Effect Transistor... more A device and method for threshold voltage programming of an Ion Sensitive Field Effect Transistor (ISFET) is of particular use in matching ISFETs in an array, which may be used in biological reaction monitoring. A circuit comprises an Ion Sensitive Field Effect Transistor (ISFET) having a floating gate and two tunnelling inputs Vt+ and Vt- coupled by capacitors Ct+ and Ct- to the floating gate for bidirectional electron tunneling to program a charge on the floating gate. The field programmable circuit enables calibration of ISFETs in an array to bring electrical parameters to a desirable point.
2012 IEEE Biomedical Circuits and Systems Conference (BioCAS), 2012
Ion sensitive field effect transistors (ISFETs) built in standard CMOS technology are effectively... more Ion sensitive field effect transistors (ISFETs) built in standard CMOS technology are effectively floating gate devices. They suffer from random trapped charges that alter their threshold voltage (Vt). This paper describes one way to program an ISFET's floating gate charges in order to bring its Vt to a desirable value using bidirectional electron tunnelling. Two inputs are capacitively coupled to the ISFET's floating gate via matched capacitors. They are used to indirectly tunnel opposite currents across their oxide isolation to the ISFET's floating gate in a controlled way. The floating gate charges are programmed using a balanced combination of these two tunnelling currents. Measured experimental results demonstrated programmability and removal of positive and negative trapped charges.
Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemic... more Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemical sensor. A single ISFET, either an N or a P device, forms the sensitive part of the circuit that may condition the signal. Each ISFET had its own ion sensitive membrane as part of it. It is shown in this work that, for devices built using a standard CMOS process, it is possible for more than one ISFET to share the same ion sensitive passivation layer. Using floating gate devices concepts, a complementary pair of ISFETs (n and p devices) shared the same ion sensitive membrane forming a fully functioning chemical switch. Its switching threshold voltage shifted by 28.33 mV per pH change of the electrolyte under test.
The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to ... more The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to its characteristics and advantages like renewable energy source compatibility, more straightforward integration with storage utilities through power electronic converters, and distributed loads. This paper presents the energy efficiency performances of a proposed LVDC supply concept and other classical PV chains architectures. A PV source was considered in the studied nanogrids. The notion of relative saved energy (RSE) was introduced to compare the studied PV systems energy performances. The obtained results revealed that the use of the proposed LVDC chain supply concept increases the nanogrid efficiency. The installed PV power source in the building should be well sized regarding the consumed power in order to register a high system RSE. The efficiency of the new LVDC architecture is 10% higher than the conventional LVDC one.
Ion sensitive field effect transistors (ISFETs) have long been used as analogue chemical sensors ... more Ion sensitive field effect transistors (ISFETs) have long been used as analogue chemical sensors particularly for biomedical applications. However, there are some applications where a “yes“/“no“ type answer regarding pH change is sufficient. For example, in DNA sequencing the question is whether a chain extension reaction took place or not. Detecting this at the sensing point reduces the sensing process to pH change threshold detection. It eliminates the need for analogue to digital conversion and facilitates an all digital sensory system. This thesis presents Novel Floating Gate ISFET based Chemical Inverters that were created with semiconductor based biomedical applications in mind. It starts by allowing two ISFETs to share the same ion sensing membrane and a common floating gate. Arranging them in a simple FG inverter configuration, their switching may be triggered by either the reference voltage or chemical pH change. In order to enhance its input noise immunity, a chemical Schm...
2016 Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC), 2016
In this paper, a simplified analytical frequency model of conducted EMI generated by a DC/DC conv... more In this paper, a simplified analytical frequency model of conducted EMI generated by a DC/DC converter is proposed. The methodology is based on the relationship between the noise source and the propagation path. The effect of the parasitic elements was taken into account in the noise sources waveforms. The proposed method was verified by comparing the improved models results with the time domain simulation results using Saber® simulation tool.
2016 7th International Renewable Energy Congress (IREC), 2016
This paper proposes a new analog technique to track the Maximum Power Point (MPP) of PV panels in... more This paper proposes a new analog technique to track the Maximum Power Point (MPP) of PV panels in PV system applications. This technique use classical and simple functions of electronic circuits. An off Grid PV system was considered to apply and validate the proposed technique. The whole circuit was implemented in circuit oriented simulator Proteus-ISIS. The obtained results have shown good efficiency of the proposed analog technique (more than 98.5%). The behavior of the proposed technique with regards to irradiation variations was described. The future of this work focuses the realization of a new specific integrated circuit of the MPPT controller.
2016 7th International Renewable Energy Congress (IREC), 2016
This paper suggests a design methodology based on the use of Genetic Algorithm (GA) for optimizin... more This paper suggests a design methodology based on the use of Genetic Algorithm (GA) for optimizing a DC/AC converter scheme used for grid-connected photovoltaic system. The converter design is optimized to reach either maximum efficiency, or minimum size, or lowest cost. To achieve such requirements, Genetic Algorithm is used to search optimal design while a non-ideal averaged model is used to model the inverter. A simulation model is developed in MATLAB/Simulink environment for the overall system. The GA is implemented in MATLAB. All optimal results show the features of the modeling and optimization technique.
2016 7th International Renewable Energy Congress (IREC), 2016
Currently, Wind farms have undergone rapid developments. They are part of the most promising tech... more Currently, Wind farms have undergone rapid developments. They are part of the most promising techniques in terms of ecology, competitiveness and job creation. Our objective in this article is modeling and simulation of the Wind System using MATLAB. The used model incorporates wind turbine controlled by a maximum power point tracking strategy, permanent magnet synchronous generator, PWM rectifier and inverter based on Hysteresis control strategy.
2013 Saudi International Electronics, Communications and Photonics Conference, 2013
The maximum theoretical sensitivity of ion sensitive field effect transistors (ISFETs) is known t... more The maximum theoretical sensitivity of ion sensitive field effect transistors (ISFETs) is known to be 59.2 mV/pH at 25°C. Devices built using standard CMOS processes generally have less sensitivity. Using floating gate νMOS concepts it is possible, without using additional circuitry or processing steps; to increase it when reflected to the input. That is by using a second electrical input that is capacitively coupled to ISFETs floating gate via a small capacitance. The ratio between the chemical sensitive passivation capacitance and this small capacitance becomes the amplification ratio of pH sensitivity referred to this input. A sensitivity of 459.17 mV/pH referred to the second input was measured. The same device had a sensitivity of 46.17 mV/pH referred to the reference voltage.
Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemic... more Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemical sensors. Each ISFET had its own ion sensitive membrane as part of it. Allowing two ISFETs to share the same ion sensing membrane, a pH inverter was built. Chemical field effect transistors (CHEMFETs) are ISFETs' derivatives. It is demonstrated here that using the ISFET based chemical switch it is possible to choose a chemical concentration threshold that when crossed the circuit changes state. A threshold of pH 6.75 was chosen and electrical output was shown to switch for pH changes from 6.5 to 7.0 and vice versa. This is effectively a digital CHEMFET basic building block as it serves as an input for further processing. This circuit can be used for chemical thresholding operations, as a digital CHEMFET transducer, in adverse applications including biomedical, chemical, and environmental industries.
Videos are full of dynamic changes along both the spatial and temporal dimensions. Large, jerky s... more Videos are full of dynamic changes along both the spatial and temporal dimensions. Large, jerky short-term motions make it difficult to extract significant changes from videos such as subtle color changes and long-term motions occurring in time-lapse sequences. In this paper, we introduce two singular value decomposition (SVD)-based video decomposition schemes to clearly reveal such changes. The first scheme involves enhancing the visual characteristics of small subtle color changes in the presence of a wide variety of motion patterns by magnifying their pixel intensities. The second scheme removes short-term motions that visually distract attention from the underlying content of video sequences such as time-lapse videos, snowing scene, and maritime surveillance. Both schemes involve the decomposition of videos into spatiotemporal slices in which each slice is further decomposed into several singular components. The low-rank components that primarily represent background and color i...
The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to ... more The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to its characteristics and advantages like renewable energy source compatibility, more straightforward integration with storage utilities through power electronic converters, and distributed loads. This paper presents the energy efficiency performances of a proposed LVDC supply concept and other classical PV chains architectures. A PV source was considered in the studied nanogrids. The notion of relative saved energy (RSE) was introduced to compare the studied PV systems energy performances. The obtained results revealed that the use of the proposed LVDC chain supply concept increases the nanogrid efficiency. The installed PV power source in the building should be well sized regarding the consumed power in order to register a high system RSE. The efficiency of the new LVDC architecture is 10% higher than the conventional LVDC one.
The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important ... more The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important part of a PV generation chain. In order to track maximum power from the solar arrays, it is necessary to control the output impedance of the PV panel, so that the circuit can be operated at its Maximum Power Point (MPP), despite the unavoidable changes in the climate conditions such as temperature and Irradiance. A new MPPT analog technique to track the Maximum Power Point (MPP) of PV arrays is proposed. This new technique uses simple and classical functions of electronic circuits. An Off-Grid PV system was considered to apply and validate the proposed new technique. The entire circuit was implemented in circuit-oriented simulator Proteus-ISIS. We present the results associated with the design, the realization, and the experimentation of a PV system equipped with a new analog MPPT command. The obtained results have shown good efficiency of analog technique (more than 98.5%). The second p...
A device and method for threshold voltage programming of an Ion Sensitive Field Effect Transistor... more A device and method for threshold voltage programming of an Ion Sensitive Field Effect Transistor (ISFET) is of particular use in matching ISFETs in an array, which may be used in biological reaction monitoring. A circuit comprises an Ion Sensitive Field Effect Transistor (ISFET) having a floating gate and two tunnelling inputs Vt+ and Vt- coupled by capacitors Ct+ and Ct- to the floating gate for bidirectional electron tunneling to program a charge on the floating gate. The field programmable circuit enables calibration of ISFETs in an array to bring electrical parameters to a desirable point.
2012 IEEE Biomedical Circuits and Systems Conference (BioCAS), 2012
Ion sensitive field effect transistors (ISFETs) built in standard CMOS technology are effectively... more Ion sensitive field effect transistors (ISFETs) built in standard CMOS technology are effectively floating gate devices. They suffer from random trapped charges that alter their threshold voltage (Vt). This paper describes one way to program an ISFET's floating gate charges in order to bring its Vt to a desirable value using bidirectional electron tunnelling. Two inputs are capacitively coupled to the ISFET's floating gate via matched capacitors. They are used to indirectly tunnel opposite currents across their oxide isolation to the ISFET's floating gate in a controlled way. The floating gate charges are programmed using a balanced combination of these two tunnelling currents. Measured experimental results demonstrated programmability and removal of positive and negative trapped charges.
Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemic... more Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemical sensor. A single ISFET, either an N or a P device, forms the sensitive part of the circuit that may condition the signal. Each ISFET had its own ion sensitive membrane as part of it. It is shown in this work that, for devices built using a standard CMOS process, it is possible for more than one ISFET to share the same ion sensitive passivation layer. Using floating gate devices concepts, a complementary pair of ISFETs (n and p devices) shared the same ion sensitive membrane forming a fully functioning chemical switch. Its switching threshold voltage shifted by 28.33 mV per pH change of the electrolyte under test.
The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to ... more The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to its characteristics and advantages like renewable energy source compatibility, more straightforward integration with storage utilities through power electronic converters, and distributed loads. This paper presents the energy efficiency performances of a proposed LVDC supply concept and other classical PV chains architectures. A PV source was considered in the studied nanogrids. The notion of relative saved energy (RSE) was introduced to compare the studied PV systems energy performances. The obtained results revealed that the use of the proposed LVDC chain supply concept increases the nanogrid efficiency. The installed PV power source in the building should be well sized regarding the consumed power in order to register a high system RSE. The efficiency of the new LVDC architecture is 10% higher than the conventional LVDC one.
Ion sensitive field effect transistors (ISFETs) have long been used as analogue chemical sensors ... more Ion sensitive field effect transistors (ISFETs) have long been used as analogue chemical sensors particularly for biomedical applications. However, there are some applications where a “yes“/“no“ type answer regarding pH change is sufficient. For example, in DNA sequencing the question is whether a chain extension reaction took place or not. Detecting this at the sensing point reduces the sensing process to pH change threshold detection. It eliminates the need for analogue to digital conversion and facilitates an all digital sensory system. This thesis presents Novel Floating Gate ISFET based Chemical Inverters that were created with semiconductor based biomedical applications in mind. It starts by allowing two ISFETs to share the same ion sensing membrane and a common floating gate. Arranging them in a simple FG inverter configuration, their switching may be triggered by either the reference voltage or chemical pH change. In order to enhance its input noise immunity, a chemical Schm...
2016 Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC), 2016
In this paper, a simplified analytical frequency model of conducted EMI generated by a DC/DC conv... more In this paper, a simplified analytical frequency model of conducted EMI generated by a DC/DC converter is proposed. The methodology is based on the relationship between the noise source and the propagation path. The effect of the parasitic elements was taken into account in the noise sources waveforms. The proposed method was verified by comparing the improved models results with the time domain simulation results using Saber® simulation tool.
2016 7th International Renewable Energy Congress (IREC), 2016
This paper proposes a new analog technique to track the Maximum Power Point (MPP) of PV panels in... more This paper proposes a new analog technique to track the Maximum Power Point (MPP) of PV panels in PV system applications. This technique use classical and simple functions of electronic circuits. An off Grid PV system was considered to apply and validate the proposed technique. The whole circuit was implemented in circuit oriented simulator Proteus-ISIS. The obtained results have shown good efficiency of the proposed analog technique (more than 98.5%). The behavior of the proposed technique with regards to irradiation variations was described. The future of this work focuses the realization of a new specific integrated circuit of the MPPT controller.
2016 7th International Renewable Energy Congress (IREC), 2016
This paper suggests a design methodology based on the use of Genetic Algorithm (GA) for optimizin... more This paper suggests a design methodology based on the use of Genetic Algorithm (GA) for optimizing a DC/AC converter scheme used for grid-connected photovoltaic system. The converter design is optimized to reach either maximum efficiency, or minimum size, or lowest cost. To achieve such requirements, Genetic Algorithm is used to search optimal design while a non-ideal averaged model is used to model the inverter. A simulation model is developed in MATLAB/Simulink environment for the overall system. The GA is implemented in MATLAB. All optimal results show the features of the modeling and optimization technique.
2016 7th International Renewable Energy Congress (IREC), 2016
Currently, Wind farms have undergone rapid developments. They are part of the most promising tech... more Currently, Wind farms have undergone rapid developments. They are part of the most promising techniques in terms of ecology, competitiveness and job creation. Our objective in this article is modeling and simulation of the Wind System using MATLAB. The used model incorporates wind turbine controlled by a maximum power point tracking strategy, permanent magnet synchronous generator, PWM rectifier and inverter based on Hysteresis control strategy.
2013 Saudi International Electronics, Communications and Photonics Conference, 2013
The maximum theoretical sensitivity of ion sensitive field effect transistors (ISFETs) is known t... more The maximum theoretical sensitivity of ion sensitive field effect transistors (ISFETs) is known to be 59.2 mV/pH at 25°C. Devices built using standard CMOS processes generally have less sensitivity. Using floating gate νMOS concepts it is possible, without using additional circuitry or processing steps; to increase it when reflected to the input. That is by using a second electrical input that is capacitively coupled to ISFETs floating gate via a small capacitance. The ratio between the chemical sensitive passivation capacitance and this small capacitance becomes the amplification ratio of pH sensitivity referred to this input. A sensitivity of 459.17 mV/pH referred to the second input was measured. The same device had a sensitivity of 46.17 mV/pH referred to the reference voltage.
Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemic... more Ion sensitive field effect transistors (ISFETs) have been used as analogue continuous time chemical sensors. Each ISFET had its own ion sensitive membrane as part of it. Allowing two ISFETs to share the same ion sensing membrane, a pH inverter was built. Chemical field effect transistors (CHEMFETs) are ISFETs' derivatives. It is demonstrated here that using the ISFET based chemical switch it is possible to choose a chemical concentration threshold that when crossed the circuit changes state. A threshold of pH 6.75 was chosen and electrical output was shown to switch for pH changes from 6.5 to 7.0 and vice versa. This is effectively a digital CHEMFET basic building block as it serves as an input for further processing. This circuit can be used for chemical thresholding operations, as a digital CHEMFET transducer, in adverse applications including biomedical, chemical, and environmental industries.
Videos are full of dynamic changes along both the spatial and temporal dimensions. Large, jerky s... more Videos are full of dynamic changes along both the spatial and temporal dimensions. Large, jerky short-term motions make it difficult to extract significant changes from videos such as subtle color changes and long-term motions occurring in time-lapse sequences. In this paper, we introduce two singular value decomposition (SVD)-based video decomposition schemes to clearly reveal such changes. The first scheme involves enhancing the visual characteristics of small subtle color changes in the presence of a wide variety of motion patterns by magnifying their pixel intensities. The second scheme removes short-term motions that visually distract attention from the underlying content of video sequences such as time-lapse videos, snowing scene, and maritime surveillance. Both schemes involve the decomposition of videos into spatiotemporal slices in which each slice is further decomposed into several singular components. The low-rank components that primarily represent background and color i...
The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to ... more The Low Voltage Direct Current (LVDC) system concept has been growing in the recent times due to its characteristics and advantages like renewable energy source compatibility, more straightforward integration with storage utilities through power electronic converters, and distributed loads. This paper presents the energy efficiency performances of a proposed LVDC supply concept and other classical PV chains architectures. A PV source was considered in the studied nanogrids. The notion of relative saved energy (RSE) was introduced to compare the studied PV systems energy performances. The obtained results revealed that the use of the proposed LVDC chain supply concept increases the nanogrid efficiency. The installed PV power source in the building should be well sized regarding the consumed power in order to register a high system RSE. The efficiency of the new LVDC architecture is 10% higher than the conventional LVDC one.
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Papers by Abdulrahman Al-Ahdal